how can I keep my soil alive

Hello I made a living soil mix
one week after started growing the myco
the next week I saw that there was something green at the bottom of the transparent box does anyone have an idea what it might be?

I plan to let it cook a month and a half... maybe more until I need to use it
And I don't know how I can keep it alive in case most of the microorganisms die due to some problem
Thankss!

(the box is outside, has holes underneath and is on bucket lids with a plastic bag covering it)

Hey I understand you make your own supper soil correct ? Just a little bit of what I know is a product called Nature's living soil. I get mine from the jungle Amazon shopping. 5 pound bag run you bout 40$ and 1 pound amends 5 lbs of medium. And only water from start to finish with amazing results. The good thing about this product is you can mix it the day you plant, no cooking required.